The invention relates to a printing fluid additive which functions as a compatibilizer between the hydrophilic material coating a media surface and the hydrophobic thermal transfer overcoat (TTO) material used in a clear protective TTO overcoat.
The use of digital printing systems has grown dramatically in recent years. This growth may be attributed to substantial improvements in print resolution and overall print quality coupled with appreciable reduction in cost. Today""s digital printers offer acceptable print quality for many commercial, business, and household applications at costs fully an order of magnitude lower than comparable products available just a few years ago. Notwithstanding their recent success, intensive research and development efforts continue toward improving digital printer print quality, while further lowering cost to the consumer.
In a digital inkjet printer, an inkjet image is formed when a precise pattern of dots is ejected from a drop-generating device known as a xe2x80x9cprintheadxe2x80x9d onto a printing medium.
Such inkjet images can be formed by either a thermal inkjet or piezoelectric inkjet system. In addition to inkjet, other systems also produce digital printed images. For example, electrostatic (laser) or electroacoustic printers are also used in to produce digital printed images.
The need exists to protect and stabilize digital printed images against, for example, scratch, abrasion, and water damage and against unwanted retransfer of ink from the digital printed image to other surfaces.
Tutt and Tunney (U.S. Pat. No. 5,847,738, issued on Jan. 8, 1999 and assigned to Eastman Kodak Co.) disclose a process for applying a protective overcoat on a digitally printed media. The protective overcoat is obtained through:
a) Charging the printed imaged element to a given polarity or applying a voltage across the surface of the element which is attracted to a conductive surface behind the element;
b) Applying colorless charged particles to the imaged element which causes them to be electrostatically attracted to the surface of the image layer; and
c) Heat-fusing the particles to obtain a protective overcoat over the entire surface of the image layer.
Colorless toner particles well-known in electrophotography are used in the coating process of Tutt and Tunney. Examples of materials mentioned in the patent are: chlorinated polyolefins, polyacrylic acid esters, cellulose derivatives, modified alkyd resins, polyesters, polyurethanes, poly(vinyl acetate), polyamides, ketone resins, polyvinylbutyral, copolymers of vinyl polymers with methacrylates or acrylates, low molecular weight polyethylene, copolymers with siloxanes, polyalkenes, and poly(styrene-co-butyl acrylate), etc.
Nagashima (U.S. Pat. No. 4,738,555 assigned to Toshiba) discloses the use of a thermal print ribbon to thermally transfer and laminate a transparent protective layer of wax, vinyl chloride, vinyl acetate, acrylic resin, styrene or epoxy on the printed image portion of a record substrate.
Tang et al. (U.S. Pat. No. 5,555,011 assigned to Eastman Kodak) disclose a method of laminating, using a thermally-transferable polymeric material, a transparent protective layer over an ink-printed image on a substrate.
Abe et al. (U.S. Pat. No. 5,954,906 assigned to Canon) discloses a method for protecting and covering a printed material on a substrate with a pressure-sensitive transferring protective covering material with at least (a) a first flexible substrate, (b) an adhesive layer, (c) a solid resin layer, and (d) a second flexible substrate, stacked in this order.
Malhotra (U.S. Pat. No. 5,612,777 assigned to Xerox) discloses a method of applying a clear, scratch-resistant, lightfast coating for a substrate having photocopied color images by first, depositing color toner images on a charge retentive surface; second, depositing a clear polymer toner material onto the charge retentive surface; and third, fusing the color toner images and clear polymer toner material onto a substrate.
Another Malhotra patent (U.S. Pat. No. 5,906,905 assigned to Xerox) discloses a method of creating photographic quality digital prints using imaging such as xerography or ink jet by, first, reverse reading toner images on a transparent substrate and then adhering the transparent substrate to a coated backing sheet, coated with a polymeric lightfastness material.
Typically, clear toner materials currently used in the industry are based on a few basic polymer types. In the table below are listed the advantages and disadvantages of these materials when used as an overcoat for digital printed images:
Core/shell polymers are well-known; such polymers typically have a hydrophilic portion and a hydrophobic portion comprising a latex particle morphology consisting of an inner xe2x80x9ccorexe2x80x9d, surrounded by an outer xe2x80x9cshellxe2x80x9d. Core/shell polymers are commonly used to disperse molecules or particles, such as pigments, which are ordinarily insoluble in water, but which, after association with the core/shell polymer, form stable dispersions in water. Encapsulation occurs when the hydrophobic portion of the polymer associates with the water-insoluble molecule, and the hydrophilic portion of the polymer disperses with water.
U.S. Pat. No. 4,597,794 discloses the dispersion of pigments in an aqueous vehicle, using aqueous binders comprising both hydrophilic and hydrophobic components. The dispersion of the pigment is followed by centrifugation to eliminate the non-dispersed components such as agglomerates. Examples of the hydrophilic component comprise polymers of monomers having a mainly additively polymerizable vinyl group, into which hydrophilic construction portions such as carboxylic acid groups, sulfonic acid groups, sulfate groups, etc. are introduced by using a predetermined amount of an alpha , beta-unsaturated monomer such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, sulfoethyl methacrylate, sulfopropyl methacrylate, sulfonated vinylnaphthalene, etc. Examples of the hydrophobic portion comprise polymers of monomers selected from the group consisting of styrene, styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, and alpha , beta-ethylenic unsaturated carboxylate of aliphatic alcohol having C8-C18. In addition to the foregoing monomers, also included are acrylonitrile, vinylidene chloride, alpha, beta-ethylenic unsaturated carboxylate, vinyl acetate, vinyl chloride, acrylamide, methacrylamide, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, N-methylol acrylamide, N-butoxymethyl acrylamide, etc.
U.S. Pat. No. 5,082,757 discloses encapsulated toner compositions comprising a core and a hydroxylated polyurethane microcapsule shell derived from the polycondensation of a polyisocyanate and a water soluble carbohydrate. The core comprises a polymer binder, pigment, dye, or mixtures thereof. Examples of the polymer binder include polymerized monomers selected from the group consisting of acrylates, methacrylates, and olefins including styrene and its derivatives.
U.S. Pat. No. 5,461,125 discloses waterborne core-shell latex polymers useful as adhesive films, rather than super-dispersion stability. The core comprises a (co)polymer comprising a (meth)acrylate ester, while the shell comprises a copolymer, the copolymer comprising (1) a nitrogen-bearing ethylenically-unsaturated free-radically polymerizable monomer, (2) at least one (meth)acrylate ester of about a C1 to C14 alcohol, and (3) an optional ethylenically-unsaturated free-radically polymerizable silane monomer, wherein the nitrogen-bearing ethylenically-unsaturated free-radically polymerizable monomer comprises about 15 to 60 wt % of the shell and wherein the core comprises about 40 to 85 wt % of the weight of the total core-shell latex particle. The polymers obtained by practicing the teachings of the disclosure have molecular weights of 400,000 or more, and the total low Tg component (less than xe2x88x9210xc2x0 C.), where Tg is the glass transition temperature, is greater than 60 wt %.
U.S. Pat. No. 5,656,071 discloses ink compositions useful for ink-jet applications. These compositions include an insoluble pigment and a polymeric dispersant. In one embodiment, the polymeric dispersant comprises block or graft copolymers comprising a hydrophilic polymeric segment (particularly an acrylate or methacrylate copolymer) and a hydrophobic polymeric segment which includes a hydrolytically stable siloxyl substituent.
Heretofore, ink-jet printers have not had printing performance and durable print properties of competitive printer technologies. The foregoing cited patents do not provide for useful, durable film-forming properties upon removal of the water or solvent. Film durability includes wet and dry rub resistance, highlighter smear-fastness, light-fastness, and waterfastness (e.g., hot and cold water, under spill, soak, and rub conditions).
In particular, formulating an ink-jet ink often involves compromising competing interests. For example, it is possible to enhance one property, such as durable film-forming of the colorant.
However, such enhancement usually results in the degradation of another property, such as printing stability associated in thermal inkjet with resistor fouling or nozzle clogging (kogation or decap-nozzle crusting).
The present invention relates to an printing fluid composition comprising an acrylic copolymer in an amount sufficient to promote adhesion of clear thermal transfer overcoat applied over a digitally printed image on media having a hydrophilic coating.
Furthermore in a preferred embodiment of the above-described printing fluid composition, the acrylic copolymer is derived from at least one hydrophilic monomer and at least one hydrophobic monomer, the acrylic copolymer having a formula
{(A)m(B)n(C)p(E)r}y
wherein A, B, C, and E are monomers as follows
A=at least one hydrophobic component contributing to improved durable, film-forming properties selected from moieties which, when homo-polymerized to a solid state, have a glass transition temperature (Tg) in the range between xe2x88x92150xc2x0 and +25xc2x0 C.;
B=at least one hydrophobic and solvent barrier moiety used to adjust the Tg of the hydrophobic component of the polymer which, when homopolymerized to a solid state, has a Tg greater than +25xc2x0 C.;
C=at least one hydrophilic component comprising a water-soluble monomer;
E=at least one moiety having at least one highly polar functional group;
and where m, n, p and r are as follows:
m=0 to 90 wt %;
n=0 to 90 wt %;
p=0 to 90 wt %;
r=0 to 90 wt %;
m+n+p+r=100wt %; and
y=1 to 100,000.
In addition, the present invention relates to a method of using adhesion promoters in printing fluids to improve adhesion of clear thermal transfer overcoats to hydrophilic coated medium, comprising
(a) printing a printing fluid composition comprising an acrylic copolymer additive onto a medium having a hydrophilic coating; and
(b) applying a clear thermal transfer overcoat to the medium printed in step (a);
wherein the acrylic copolymer additive in the printing fluid composition is in an amount sufficient to promote adhesion of clear thermal transfer overcoat applied over an image printed with the printing fluid composition.
Furthermore, in preferred embodiment of the above-described method, the acrylic copolymer is derived from both a hydrophilic monomer and a hydrophobic monomer, the acrylic copolymer having a formula
{(A)m(B)n(C)p(E)r}y
wherein A, B, C, and E are monomers as follows
A=at least one hydrophobic component contributing to improved durable, film-forming properties selected from moieties which, when homo-polymerized to a solid state, have a glass transition temperature (Tg) in the range between xe2x88x92150xc2x0 and +25xc2x0 C.;
B=at least one hydrophobic and solvent barrier moiety used to adjust the Tg of the hydrophobic component of the polymer which, when homopolymerized to a solid state, has a Tg greater than +25xc2x0 C.;
C=at least one hydrophilic component comprising a water-soluble monomer;
E=at least one moiety having at least one highly polar functional group;
and where m, n, p and r are as follows:
m=0 to 90 wt %;
n=0 to 90 wt %;
p=0 to 90 wt %;
r=0 to 90 wt %;
m+n+p+r=100 wt %; and
y=1 to 1 00,000.
If a layer or layers of clear thermoplastic material could be applied to digitally printed media in the form of a clear hydrophobic thermal transfer overcoat (TTO), such a TTO would protect the media from the effects of water, humidity, dirt, stains, organic solvents, etc. It also would allow the color qualities of the inks in the printed images to last for a longer period of time than those printed images on a printed medium which is unprotected and directly exposed over time to air, light, changes of temperature, etc. These potential protective and preservative effects of clear hydrophobic TTO on digitally printed media notwithstanding, it has been found that, because of its hydrophobicity, TTO does not adhere well either to the hydrophilic materials, such as, for example, gelatin, polyvinyl alcohol, swellable coating and other hydrophilic materials used to coat the media surface itself or to the digital printer ink-printed images which are applied to the media surface. This is because the digital printer inks used in the printed images and the coating materials used on the media surface are both predominantly hydrophilic, thus adhering well to each other but not to the hydrophobic material used in the clear TTO. Because of this problem of poor adherence between the hydrophobic TTO coatings and the hydrophilic digital-printer inks and media coatings, clear TTO overcoatings have not been found workable to protect digitally printed media. When hydrophobic thermal transfer overcoating is applied to such digitally printed media, the poor adhesion of the overcoating to the hydrophilic ink and/or media coating results in an overcoat which cracks, flakes and can eventually peel off totally from the medium.
It is usually the case in digital printing on hydrophilic material-coated media, that there are virtually no areas of the media left uncovered by digitally printed ink images. Thus, if a digital printer ink were developed which was compatible and adherent with both hydrophilic material-coated media and hydrophobic clear thermal transfer overcoat, the protective, preservative qualities of clear TTO could be utilized with these digitally printed photographs. Thus in one embodiment, the digital printing fluid of the present invention is an ink, the digital printing fluid of the present invention further comprising colorant material. In another embodiment, the digital printing fluid has no colorant and is applied to the media, either alone without ink or separately from the ink. In any case, the compatibilizing additive of the printng fluid ends up between the media coating and the thermal transfer overcoat,
When applied to a media in the printing fluid, with or without ink colorant, the additive in the digital printing fluid allows the hydrophilic material-coated media to be compatible and adherent with the hydrophobic clear thermal transfer overcoating. In a preferred embodiment, this printing fluid additive compatibilizer allows images digitally printed on media to obtain the significant protective and preservative benefits of a clear TTO overcoating.
Monomers
The acrylic copolymers used in the presently claimed invention are derived from at least one hydrophilic portion and at least one hydrophobic portion and have the following general structure given by the formula
{(A)m(B)n(C)p(E)r}y
wherein A, B, C, and E are monomers as follows
A=at least one hydrophobic component contributing to improved durable, film-forming properties selected from moieties which, when homo-polymerized to a solid state, have a glass transition temperature (Tg) in the range between xe2x88x92150xc2x0 and +25xc2x0 C.;
B=at least one hydrophobic and solvent barrier moiety used to adjust the Tg of the hydrophobic component of the polymer which, when homopolymerized to a solid state, has a Tg greater than +25xc2x0 C.;
C=at least one hydrophilic component comprising a water-soluble monomer;
E=at least one moiety having at least one highly polar functional group;
and where m, n, p and r are as follows:
m 0 to 90 wt %, preferably 10 to 60 wt %, and more preferably 15 to 50 wt %;
n=0 to 90 wt %, preferably 10 to 60 wt %, and more preferably 15 to 50 wt %;
p=0 to 90 wt %, preferably 10 to 60 wt %, and more preferably 15 to 50 wt %;
r=0 to 90 wt %, preferably 0.01 to 60 wt %, and more preferably 1 to 40 wt %;
m+n+p+r=100wt %; and
y=1 to 100,000, preferably 10 to 10,000, and more preferably 100 to 1,000.
Preferably, either m or n is non-zero.
The molecular weight (weight average) of the acrylic copolymer is between about 100 and 2,000,000, preferably between about 1,000 and 500,000, and most preferably between about 5,000 and 300,000.
The Tg of the acrylic copolymers is within the range of about xe2x88x92100xc2x0 to +100xc2x0 C., preferably within the range of about xe2x88x9230xc2x0 to +30xc2x0 C., and more preferably within the range of about 0xc2x0 to +30xc2x0 C.
The molecular weight (weight average) of the acrylic copolymer is between about 1,000 and 2,000,000, preferably between about 5,000 and 500,000, and most preferably between about 10,000 and 70,000.
The copolymer of the present system is designed to have both hydrophobic and hydrophilic moieties. It can also be associated with one or more surfactants to form a polymer/surfactant system. Thus, the polymer or polymer/surfactant system is both (1) water-dispersible, and includes water-soluble polar groups, which are present in sufficient quantity to suspend a pigment particle, and (2) hydrophobic, with a substantial fraction of the polymer containing hydrophobic moieties that are either highly water-resistant or even water-insoluble.
The hydrophobic A moiety allows the copolymer to have a Tg sufficient to permit formation of a film with other copolymer molecules containing the A moiety. The film formation results upon drying (removal of water).
The hydrophobic B moiety in combination with the hydrophobic A moiety provide the copolymer with resistance to environmental solvents, such as water and those found in highlighter pens. Additional environmental solvents can be found in rain, coffee, soda pop, body oils, soils, hot water, etc.
The hydrophilic C moiety may be provided in the copolymer itself, as shown in the formula. At least one C moiety may be present, and is water-soluble. Alternatively, the C moiety may be provided by one or more surfactants, to form a polymer/surfactant system. Any of the ionic (anionic and cationic), non-ionic, and zwitterionic (amphoteric) surfactants may be employed. A representative listing of applicable surfactant can be found in McCutcheon""s Emulsifiers and Detergents, North American Edition, 1997, McCutcheon""s Division, MC Publishing Co. 175 Rock road, Glen Rock, N.J. 07452 USA Examples of surfactants that may be beneficially employed in the practice of the present invention include: TERGITOLs, which are polyethylene or polypropylene oxide ethers; alkyl phenyl polyethylene oxides available under the tradename TRITONs,; BRIJs, which are polyethylene or polypropylene oxide ethers; PLURONICs, which are also polyethylene/o polypropylene oxide copolymers from BASF; and the SURFYNOLs, which are acetylenic ethoxylated diols; polyethylene oxide (POE) esters; POE diesters; POE amines; protonated POE amines; POE amides; the polypropylene analogs of the foregoing POE compounds; dimethicone copolyols; quaternary ammonium compounds; AEROSOLS, including sulfosuccinates; ethoxylates, amine oxides, and betaines.
Preferred examples of non-ionic surfactants include, but are not limited to, BRIJs, which are polyethylene oxide ethers, available from ICI Surfactants (specific examples include the following BRIJs: 30, 35, 52, 56, 58, 72, 76,78, 92, 97, and 98); TWEENs, which are derivatives of polyethylene oxides, available from ICI Surfactants (specific examples include the following TWEENs: 20, 40, 60, 80, and 85); SOLSPERSE 27,000, which is an aromatic ethoxylate, available from Avecia; SPAN 85, which is available from Air Products; and SURFYNOLs, which are acetylenic ethylene oxides available from Air Products. Examples of anionic surfactants include AEROSOL DPOS 45, which is a sulfate, available from Cytec Industries; sodium octadecyl sulfonate; dioctyl ester of sodium sulfosuccinic acid; AEROSOL OT 100%, which is a sulfate, available from American Cyanamid; and sodium lauryl sulfonate. If used, the amount of surfactant ranges from about 0.001 to 30 wt %, and the balance the polymer.
Also optionally, one or more ionic water-soluble moieties E may be present.
One monomer may be employed to provide one or more of the foregoing functions. Alternatively, one function may be provided by one or more of the foregoing moieties. However, in many instances, a single monomer provides a single function.
The copolymer(s) of the present invention is prepared by emulsifying the monomeric components, and then conducting a free-radical polymerization in water. Free-radical polymerization involves employing a free-radical initiator. A concentration of about 0.001 to 10 wt % of the initiator is employed in the total monomer system. Examples of suitable free-radical initiators include, but are not limited to, ammonium persulfate, potassium persulfate, hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, TRIGONOX 21, and PERKADOX 16. In one possible embodiment, the resulting copolymer is a random copolymer. In another possible embodiment, the resulting copolymer is a block copolymer.
One skilled in this art would understand that the copolymer(s) can also be prepared by conventional condensation techniques. Once a film is formed from the copolymer and water is removed, as by dehydration under ambient conditions, the film is essentially impervious to water, and the copolymer is not capable of being redispersed with water. If the copolymer or copolymer/surfactant system is associated with pigment particles, and the pigment with copolymer or copolymer/surfactant system is deposited on a surface, such as paper, then the pigment particles are trapped within or beneath the film on the surface, and are thus protected from the effects of water and environmental solvents.
As stated above, the A moiety is a hydrophobic component for controlling solubility in organic solvents selected from monomer(s) that form homopolymers having a Tg in the range between xe2x88x92150xc2x0 and +25xc2x0 C. The A moiety is preferably selected from ethylenically-substituted compounds given by (A):
C(R1)(R2)xe2x95x90C(R3)R4R5R6
where R1 and R2 are independently hydrogen, halogen, alkyl, aryl, or substituted alkyl or aryl;
R3 is hydrogen, halogen, saturated or unsaturated alkyl, alkoxy, aryl, or substituted alkyl, alkoxy, or aryl,
R4 is direct bond, O, CO, NH, halogen, saturated or unsaturated alkyl, aryl, or substituted alkyl, aryl, or CN, R5 is absent (if R4 is alkyl, aryl, or substituted alkyl or aryl), direct bond, hydrogen, NH, O, alkyl, alkylene, aryl, or substituted alkyl, alkylene, or aryl, and
R6 is absent (if R4 is alkyl, aryl, or substituted alkyl or aryl or if R5 is hydrogen, alkyl, aryl, or substituted alkyl or aryl), NH2, saturated or unsaturated alkyl, alkoxy, aryl, aroxy, or substituted alkyl or aryl.
The alkyl, alkoxy, alkylene, and aryl chains each contain more than one carbon atom and less than 40 carbon atoms. Preferably, the R4 functionality is an electron acceptor moiety.
One preferred embodiment of formula (A) is the following general structure (A1): 
where
Rxe2x80x23=H, halogen, alkyl, aryl or substituted alkyl or aryl;
Rxe2x80x25=direct bond, O, or NH; and
Rxe2x80x26=alkyl, substituted alkyl, alkylaryl or substituted alkylaryl and aralkyl in which the length of alkyl, alkylaryl or aralkyl chain is given as the number of C atoms between 2 and 18; and alkyl or aryl siloxanes.
Examples for structure (A1) include, but are not limited to:
(A1-1) ethyl acrylate;
(A1-2) ethyl methacrylate;
(A1-3) benzyl acrylate;
(A1-4) benzyl methacrylate;
(A1-5) propyl acrylate;
(A1-6) propyl methacrylate;
(A1-7) iso-propyl acrylate;
(A1-8) iso-propyl methacrylate;
(A1-9) butyl acrylate;
(A1-10) butyl methacrylate;
(A1-11) hexyl acrylate;
(A1-12) hexyl methacrylate;
(A1-13) octadecyl methacrylate;
(A1-14) octadecyl acrylate;
(A1-15) lauryl methacrylate;
(A1-16) lauryl acrylate;
(A1-17) hydroxyethyl acrylate;
(A1-18) hydroxyethyl methacrylate;
(A1-19) hydroxyhexyl acrylate;
(A1-20) hydroxyhexyl methacrylate;
(A1-21) hydroxyoctadecyl acrylate;
(A1-22) hydroxyoctadecyl methacrylate;
(A1-23) hydroxylauryl methacrylate;
(A1-24) hydroxylauryl acrylate;
(A1-25) phenethyl acrylate;
(A1-26) phenethyl methacrylate;
(A1-27) 6-phenylhexyl acrylate;
(A1-28) 6-phenylhexyl methacrylate;
(A1-29) phenyllauryl acrylate;
(A1-30) phenyllauryl methacrylate;
(A1-31) 3-nitrophenyl-6-hexyl methacrylate;
(A1-32) 3-nitrophenyl-18-octadecyl acrylate;
(A1-33) ethyleneglycol dicyclopentyl ether acrylate;
(A1-34) vinyl ethyl ketone;
(A1-35) vinyl propyl ketone;
(A1-36) vinyl hexyl ketone;
(A1-37) vinyl octyl ketone;
(A1-38) vinyl butyl ketone;
(A1-39) cyclohexyl acrylate;
(A1-40) 3-methacryloxypropyldimethylmethoxysilane;
(A1-41) 3-methacryloxypropylmethyldimethoxysilane;
(A1-42) 3-methacryloxypropylpentamethyldisiloxane;
(A1-43) 3-methacryloxypropyltris(trimethylsiloxy)silane;
(A1-44) 3-acryloxypropyldimethy,methoxysilane;
(A1-45) acryloxypropyhlethyldimethoxysilane;
(A1-46) trifluoromethyl styrene;
(A1-47) trifluoromethyl acrylate;
(A1-48) trifluoromethyl methacrylate;
(A1-49) tetrafluoropropyl acryl ate;
(A1-49) tetrafluoropropyl methacrylate;
(A1-51) heptafluorobutyl methacrylate;
(A1-52) iso-butyl acrylate;
(A1-53) iso-butyl methacrylate;
(A1-54) 2-ethylhexyl acrylate;
(A1-55) 2-ethylhexyl methacrylate;
(A1-56) iso-octyl acrylate; and
(A1-57) iso-octyl methacrylate.
Another preferred embodiment for formula (A) is the following general structure (A2): 
where
Rxe2x80x23=same definition as that of structure (A1) above; and
R7=R8 same or different combinations of Rxe2x80x26 in structure (A1) above.
An example for structure (A2) includes, but is not limited to:
(A2-1) N,N-dihexyl acrylamide; and
(A2-2) N,N-dioctyl acrylamide.
Yet another preferred embodiment for formula (A) is the following general structure (A3): 
where Rxe2x80x23=same definition as that of structure (A1);
Rxe2x80x25=same definition as that of structure (A1);
Rxe2x80x26=alkylene, arylene, substituted alkylene or arylene; and
R9 and R10 are independently selected from H, alkyl, substituted alkyl, alkylaryl or substituted alkylaryl in which the length of alkyl and alkylaryl chains each comprise between 2 and 40 carbon atoms. Alternatively, R9 and R10 together may form a 5- or 6-membered ring.
Examples for structure (A3) include, but are not limited to:
(A3-1) aminoethyl acrylate;
(A3-2) aminopropyl acrylate;
(A3-3) aminopropyl methacrylate;
(A3-4) aminoisopropyl acrylate;
(A3-5) aminoisopropyl methacrylate;
(A3-6) aminobutyl acrylate;
(A3-7) aminobutyl methacrylate;
(A3-8) aminohexyl acrylate;
(A3-9) aminohexyl methacrylate;
(A3-10) amino octadecyl methacrylate;
(A3-11) aminooctadecyl acrylate;
(A3-12) aminolauryl methacrylate;
(A3-13) aminolauryl acrylate;
(A3-14) N,N-dimethylaminoethyl acrylate;
(A3-15) N,N-dimethylaminoethyl methacrylate;
(A3-16) N,N-diethylaminoethyl acrylate;
(A3-17) N,N-dimethylaminoethyl methacrylate; and
(A3-18) piperidino-N-ethyl acrylate.
Still another preferred embodiment for formula (A) is the following general structure (A4): 
where:
Rxe2x80x23=H, halogen, alkyl, aryl, substituted alkyl or aryl;
Rxe2x80x25=direct bond, CO, alkylene, arylene, substituted alkylene or arylene; and
Rxe2x80x26=alkyl, aryl, substituted alkyl or aryl.
Examples for structure (A4) include, but are not limited to:
(A4-1) vinyl propionate;
(A4-2) vinyl acetate;
(A4-3) vinyl butyrate;
(A4-4) vinyl butyl ether;
(A4-5) vinyl propyl ether;
(A4-6) vinyl neodecanoate;
(A4-7) vinyl neononate and
(A4-8) vinyl pivalate.
As stated above, the B moiety is hydrophobic and is a solvent barrier composed of monomer(s) that form homopolymers having a Tg greater than 25xc2x0 C. The B moiety has the general structure given by formula (B)
CR1R2xe2x95x90C(R3)Rxe2x80x34R5xe2x80x3Rxe2x80x36
where
R1 and R2 are independently hydrogen, or halogen;
R3 is hydrogen, halogen, saturated or unsaturated alkyl, alkoxy, aryl, or substituted alkyl, alkoxy, or aryl,
R4 is direct bond, O, CO, NH, halogen, saturated or unsaturated alkyl, aryl, or substituted alkyl, aryl, or CN,
R5 is absent (if R4 is CN, alkyl, aryl, or substituted alkyl or aryl), direct bond, hydrogen, NH, O, alkyl, alkylene, aryl, or substituted alkyl, alkylene, or aryl, and
R6 is absent (if R4 is alkyl, aryl, or substituted alkyl or aryl or if R5 is hydrogen, alkyl, aryl, or substituted alkyl or aryl), NH2, saturated or unsaturated alkyl, alkoxy, aryl, aroxy, or substituted alkyl or aryl. The alkyl, alkoxy, alkylene, aryl, aroxy chains each contain from 1 to 40 carbon atoms. Additionally, R1 and R2 and R3 and R4 can each form a ring; one example of a ring compound so formed includes, but is not limited to, polyvinyl butyral. Further, Rxe2x80x34 and R5 can form a ring through either nitrogen or oxygen.
Formula (B) is seen to be substantially the same as formula (A), but with some differences in the substituent groups, which provide a homopolymer of these monomers with the higher Tg of at least 25xc2x0 C.
One preferred embodiment of formula (B) is the following general structure (B1):
CH2xe2x95x90CRxe2x80x2xe2x80x35Rxe2x80x2xe2x80x36
where
Rxe2x80x2xe2x80x35=hydrogen, alkyl, alkoxy, aryl or halogen; and
Rxe2x80x2xe2x80x36=H, aryl, alkyl (with one carbon atom), amino, ester, epoxy component containing groups, and fluoroalkyl derivatives.
Examples for formula (B1) include, but are not limited to;
(B1-1) ethylene;
(B1-2) styrene;
(B1-3) vinyl carbazole;
(B1-4) vinyl naphthalene;
(B1-5) vinyl anthracene;
(B1-6) vinyl pyrene;
(B1-7) methyl methacrylate;
(B1-8) methyl acrylate;
(B1-9) alpha-methyl styrene;
(B1-10) dimethylstyrene;
(B1-11) methylstyrene;
(B1-12) vinylbiphenyl;
(B1-13) glycidyl acrylate;
(B1-14) glycidyl methacrylate;
(B1-15) glycidyl propylene;
(B1-16) 2-methyl-2-vinyl oxirane;
(B1-17) vinyl pyridine;
(B1-18) aminoethyl methacrylate; and
(B1-19) aminoethylphenyl acrylate.
Another preferred embodiment of formula (B) is the following general structure (B2): 
Where R14 and R15 are independently selected from H, halogen, alkyl, aryl, substituted alkyl and aryl; alternatively, R14 and R15 are in the form of a closed ring; and
R16 is H, halogen, alkyl, aryl, substituted alkyl or aryl, or unsaturated alkyl.
Examples for formula (B2) include, but are not limited to:
(B2-1) maleimide;
(B2-2) N-phenyl maleimide;
(B2-3) N-hexyl maleimide;
(B2-4) N-vinylphthalimide; and
(B2-5) N-vinyl maleimide.
As stated above, the C moiety is an optional hydrophilic component. The C moiety is selected from a wide variety of monomers such as poly(ethylene glycol) units having general formula (C1), vinyl pyrrolidones having general formula (C2), vinyl imidazoles having general formula (C3) and acrylamides having general formula (C4), all of which polymerize to form water-soluble polymers.
The general structure of formula (C1) is 
where
R1=H, halogen, alkyl, aryl, or substituted alkyl or aryl;
R2=direct bond, O, CO, NH, or CONH;
R3=OH, (CH2CH2O)yR4, (CH2CH(CH3)O)yR4, or (CH2CH(C2H5)O)yR4 or the thioester analogs: SH, (CH2CH2S)yR4, (CH2CH(CH3)S)yR4 or (CH2CH(C2H5)S)yR4;
y=1 to 200; and
R4=alkyl, aryl, substituted alkyl or aryl.
Examples for general structure (C1) include, but are not limited to:
(C1-1) poly(ethylene glycol) methyl ether acrylate of average molecular weight 404;
(C1-2) poly(ethylene glycol) methyl ether methacrylate of average molecular weight 418;
(C1-3) poly(ethylene glycol) methyl ether methacrylate of average molecular weight 2068;
(C1-4) poly(ethylene glycol) methyl ether acrylate of average molecular weight 2054; and
(C1-5) polyvinyl alcohol.
The general structure of formula (C2) is 
where R1 and R2 are independently selected from xe2x80x94H, halogen, alkyl, aryl, and substituted alkyl and aryl.
Examples for general structure (C2) include, but are not limited to:
(C2-1) vinyl pyrrolidone;
(C2-2) vinyl 4-methylpyrrolidone; and
(C2-3) vinyl 4-phenylpyrrolidone.
The general structure of formula (C3) is 
where R1 and R2 are independently selected from H, halogen, alkyl, aryl, and substituted alkyl and aryl.
Examples for general structure (C3) include, but are not limited to:
(C3-1) vinyl imidazole;
(C3-2) vinyl 4-methylimidazole; and
(C3-3) vinyl 4-phenylimidazole.
The general structure of formula (C4) is 
where
R1 is H, halogen, alkyl, aryl or substituted alkyl or aryl; and
R2 and R3 are independently selected from H, alkyl, aryl and substituted alkyl and aryl; alternatively, R2 and R3 can form a ring, either aliphatic or aromatic.
Examples for the general structure (C4) include, but are not limited to:
(C4-1) acrylamide;
(C4-2) methacrylamide;
(C4-3) N,N-dimethyl acrylamide;
(C4-4) N-methyl acrylamide;
(C4-5) N-methyl methacrylamide;
(C4-6) aryloxy piperidine; and
(C4-7) N,N-diethyl acrylamide.
As stated above, the E moiety is a highly polar functional group composed of moieties having the general structure given by formulae (E1) to (E10).
The general structure of formula (E1) is
CH(R1)xe2x95x90C(R2)R3COOH
where
R1=H, COOH, COOR4;
R2=COOH, H, halogen, alkyl, aryl, alkoxyl, or substituted alkyl, aryl or alkoxyl;
R3=direct bond, alkylene, arylene or substituted alkylene or arylene; and
R4=alkyl, aryl, substituted alkyl or aryl.
Examples for structure (E1) include, but are not limited to:
(E1-1) acrylic acid;
(E1-2) methacrylic acid;
(E1-3) chloromethacrylic acid;
(E1-4) maleic acid;
(E1-5) maleic acid monoethyl ester;
(E1-6) crotonic acid;
(E1-7) itaconic acid and
(E1-8) itaconic acid monoethyl ester.
The general structure of formula (E2) is
xe2x80x83CH2xe2x95x90CHR1NR2R3
where
R1=alkylene, arylene, substituted alkylene, arylene, or xe2x80x94SO2; and
R2 and R3 are independently selected from H, alkyl, aryl, or substituted alkyl, aryl or alkoxyl; alternatively, R2 and R3 can be combined to form a ring, either aliphatic or aromatic.
Examples for structure (E2) include, but are not limited to:
(E2-1) allylamine;
(E2-2) N,N-diethylallylamine; and
(E2-3) vinyl sulfonamide.
The general structure of formula (E3) is
y(CH2=CHR1COOxe2x88x92)My+
where
R1xe2x95x90alkylene, arylene, substituted alkylene or arylene;
y=1 to 4; and
My+=NH4+, Li+, Na+, K+, Ca2+, Mg2+, Al3+, Ti4+, triethylammonium, diethylammonium pyrridinium, etc.
Examples for structure (E3) include, but are not limited to:
(E3-1) sodium acrylate;
(E3-2) sodium methacrylate;
(E3-3) ammonium acrylate; and
(E3-4) ammonium methacrylate.
The general structure of formula (E4) is 
where
R1=alkylene, arylene, substituted alkylene or arylene, COO, or cyclic ring containing nitrogen;
R2, R3, and R4 are independently selected from H, alkyl, aryl, alkoxyl, or substituted alkyl, aryl or alkoxyl;
z=1 to 4; and
X=halogen, BF4, PF6, ClO4, SCN, CNO, CNS.
Examples for general structure (E4) include, but are not limited to:
(E4-1) acrylamidopropanetriethylammonium chloride;
(E4-2) methacrylamidopropanetriethylammonium chloride; and
(E4-3) vinylpyridine hydrochloride.
The general structure of formula (E5) is 
where
R1=H, alkyl, aryl, alkoxyl, substituted alkyl, aryl or alkoxyl;
R2=direct bond, alkylene, arylene or substituted alkylene or arylene;
z=1 to 4; and
Mz+=NH4+, Li+, Na+, K+, Ca2+, Mg2+, Al3+, Ti4+, triethylammonium, diethylammonium, pyrridinium, etc.
Examples for the general structure (E5) include, but are not limited to:
(E5-1) sodium vinyl phosphonate; and
(E5-2) sodium 1-methylvinylphosphonate.
The general structure of formula (E6) 
where
R1=H, alkyl, aryl, alkoxyl, substituted alkyl, aryl or alkoxyl;
R2=direct bond, xe2x80x94COOR3, arylene, alkylene, or xe2x80x94CONHR3;
R3=alkylene, arylene, substituted alkylene or arylene, or fluoroalkylene;
z=1 to 4; and
Mz+=NH4+, Li+, Na+, K+, Ca2+, Mg2+, Al3+, Ti4+, etc.
Examples for the general structure (E6) include, but are not limited to:
(E6-1) sodium vinyl sulfonate;
(E6-2) sodium 1-methylvinylsulfonate;
(E6-3) sodium styrenesulfonate;
(E6-4) sodium acrylamidopropanesulfonate;
(E6-5) sodium methacrylamidopropanesulfonate; and
(E6-6) sodium vinyl morpholine sulfonate.
Additional E moieties include the following salts:
(E7) sulfonium salts;
(E8) carbonium salts;
(E9) pyrrilinium salt and thio pyrrilinium salt; and
(E10) tetrazolium salt.
The sulfonium salts have the following structure (E7): 
where
R1=H, halogen, alkyl, or aryl;
R2=CO, O;
R3=direct bond, NH;
R4=alkyl or aryl; and
X=Cl, Br, BF4, ClO4, I, or NO3.
The carbonium salts have the following structure (E8): 
where
R1=H, halogen, alkyl, or aryl;
R2=CO, O;
R3=direct bond, NH, alkylene, or arylene;
R4 and R5 are independently selected from alkyl or aryl; and
X=SbF5, FSO3.
The pyrrilinium and thio-pyrrilinium salts have the following structure (E9): 
wherein
Y=O or S;
R1=H, halogen, alkyl, or aryl;
R2=CO, O;
R3=direct bond, NH, alkylene, or arylene;
X=Cl, Br, I, ClO4, BF4, etc.
Copolymers that fall within the scope of the formula include, but are not limited to, the following examples, which may be characterized as A-B-E, A-B-C-E, A-E, or B-E polymers,; these copolymers promote adhesion between the media and the overcoat:
P1. (hexyl acrylate)40(methyl methacrylate)40(acrylic acid)20 
P2. (hexyl acrylate)60 (methyl methacrylate)20(metbacrylic acid)20 
P3. (hexyl acrylate)40(methyl methacrylate)40(maleic acid)20 
P4. (hexyl acrylate)40(methyl methacrylate)40(vinyl benzoic acid)20 
P5. (hexyl acrylate)40(methyl methacrylate)40(vinyl sulfonamide)20 
P6. (hexyl acrylate)40(methyl methacrylate)40(sodium acrylate)20 
P7. (hexyl acrylate)40 (methyl methacrylate)40 (ammonium acrylate)20 
P8. (hexyl acrylate)40(methyl methacrylate)40(ammonium methacrylate)20 
P9. (ethyl acrylate)40(methyl methacrylate)40(acrylamidopropanetriethylammonium chloride)20 
P10. (propyl acrylate)40(methyl methacrylate)40(vinyl pyridine hydrochloride)20 
P11. (butyl acrylate)40(methyl methacrylate)40(sodium vinyl phosphate)20 
P12. (hexyl acrylate)40(methyl methacrylate)40(sodium styrene sulfonate)20 
P13. (hexyl acrylate)30(methyl methacrylate)50(sodium acrylamidopropanesulfonate)20 
P14. (styrene)80(acrylic acid)20 
P15. (styrene)60(acrylic acid)40 
P16. (styrene)40(methyl methacrylate)40(acrylic acid)20 
P17. (ethyl acrylate)60(acrylic acid)40 
P18. (styrene)40(ethyl acrylate)40(acrylic acid)20 
P19. (methyl methacrylate)32(hexyl acrylate)46(poly(ethylene glycol) methyl ether acrylate, mw=404)12 (acrylic acid)10 
P20. (hexyl acrylate)40(methyl methacrylate)40(sodium xylene sulfonate)20